title: Continuously tunable microdroplet-laser in a microfluidic channel.
abstract: This paper describes the generation and optical characterization of a series of dye-doped droplet-based optical microcavities with continuously decreasing radius in a microfluidic channel. A flow-focusing nozzle generated the droplets (~21 μm in radius) using benzyl alcohol as the disperse phase and water as the continuous phase. As these drops moved down the channel, they dissolved, and their size decreased. The emission characteristics from the drops could be matched to the whispering gallery modes from spherical micro-cavities. The wavelength of emission from the drops changed from 700 to 620 nm as the radius of the drops decreased from 21 μm to 7 μm. This range of tunability in wavelengths was larger than that reported in previous work on droplet-based cavities.
authors.affiliation: Department of Chemistry and Chemical Biology, Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Sindy K Y
authors.initials: SK
authors.lastname: Tang
authors.forename: Ratmir
authors.initials: R
authors.lastname: Derda
authors.forename: Qimin
authors.initials: Q
authors.lastname: Quan
authors.forename: Marko
authors.initials: M
authors.lastname: Lončar
authors.forename: George M
authors.initials: GM
authors.lastname: Whitesides
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D007834:Lasers; D007909:Lenses; D044085:Microfluidics / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*; D012996:Solutions / Q000737:chemistry
chemical_list: D012996:Solutions